Trying to breed my Molly's and platys, but they don't seem to be interested in each other. I have 2 female and 1 male of each species(molly's and platy' s) the temp. Stays between 76' & 78' F, the water has aquarium salt in it, only as much as the box recommended. There are plenty of rocks for hiding and plants in the tank. Oh and its a 30 gal. (U.S) if that matters, what am I doing wrong...?

What are you doing wrong? Possibly nothing except being too impatient Are the fish of each species a similar size? If the male is too small he will not be able to manage to do the deed.Rocks are unnecessary as these fish do not use them to hide, unless they are large and break up line of sight.Plenty of soft leaved plants like ambulia, cabomba, Java moss, water sprite and Indian fern.Is it possible they are breeding but you have not noticed? If well planted, the fry are good at hiding. If not as well planted as you think then they will be eaten.

As the previous poster says, be careful what you wish for. I keep a close eye on my Platties and Mollies. Whenever one of the fmales looks ready to drop a brood (I trust you have read up on how to recognise a pregnant Molly or Platty - Gravid spot, size, shape etc?) I put it in a breeding net with some live plants for the young to hide in and then remove the mother and put her back in the main tank when she has finished giving birth. The young can then be brought on in the breeding net of a separate tank where they will not get eaten. (I am fortunate in the fact that my local Tropical Fish Shop will buy any young that I breed)My Guppies are a different matter. I keep my Guppies in the a heavily planted tank and let nature take it's course while the Guppies "do their own thing". The fact that the tank is very heavily planted means that many of the young survive and don't get themselves eaten by the adults. All I do is wait for the young to grow to a "saleable size" and then thin them out, keeping any that look "really special" for my breeding stock.You haven't told us roughly how old or what size your fish are - That may have a bearing on why they haven't had any young yet unless they have and you haven't noticed - Unless your males are a bunch of gays! .As has no doubt already been said sometimes you just have to give nature a little patience, but be aware that once they start to breed you might wish they hadn't!

I wonder how he got on? The original post was 2013 so hopefully he has had success since then You are very lucky your local shop will take your fry as ours will not.It pays also to give your females a rest between broods or they will die young.